The present disclosure relates to optical scanning devices that form a latent image on a surface scanned by exposure to light, and also relates to image forming apparatuses incorporating such optical scanning devices, such as copiers, printers, facsimile machines, and multifunction peripherals having the functions of more than one of those.
An optical scanning device incorporated in copiers, printers, and the like typically includes a light source, a polygon mirror (rotary multiple-face mirror) which achieves scanning by deflecting a light beam from the light source, an fθ lens which focuses the light beam deflected by the polygon mirror on a scanned surface, and a housing to which those components are fastened.
The optical scanning device is extremely sensitive to dust, dirt, and other particulate foreign matter. Dust settled on the fθ lens or the polygon mirror intercepts the light beam and reduces the amount of light, leading to defects in images, such as stripes and uneven density. To avoid that, a housing, a cover member, and the like are used to form a housing space in which to house the polygon mirror and the fθ lens.
In the housing, a light emission opening is formed through which the light beam having traveled from the light source via the polygon mirror and the fθ lens is emitted toward a photosensitive drum. To the housing, a light transmitting member which transmits light is fastened with tape, adhesive, or the like.